Poration



Patent ed May 19, 1931 {UNITED "STATES PATENT OFFICE FRANKLIN B. HUNT, OF CHICAGO, ILLINOIS, ASSIGNOB TO THE LIQUID CABBONIC COR- PORATION, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE REFRIGERATING SYSTEM Application liled August 15, 1930. Serial No. 475,416.

The Object of my invention is to provide a refrigerating system comprising a plurality of heat-absorbing elements so connected to a single regenerator that the various heat-abr sorbing elements, when properly placed in 'independent refrigerating chambers, may

have different minimum operating temperatures. 1 1 v The present invention is a development of the invention forming the subject matter of my Patent Number 1,7 46,896.

The accompanying drawing diagramatically illustrates my invention as embodied in a refrigerating, system of the mechanical compression type. In the drawing, 10 indicates a mechanical compressor having the suction line 11 and the discharge line 12 which leads into a condenser 13. Leading from'condenser 13 is the refrigerant discharge line 14 from which lead branches 15, 16, 17 '(etc.)

- to heat-absorbing units 18, 19, 20 (etc), re-

spectively, of the constant liquid-level type commonly referred to as boilers, the discharge end of each of said branches, within its respective boiler, being controlled by a float-controlled valveV dependent upon the liquid level in the boiler. In each branch v15, #16, 17, is an expansion valve E, ofcommon and well known construction.

A portion of branch 15, between expansion valve E and-boiler 18, is passed through a refrigerating chamber separate and distinct from the refrigerating'chamber 31 in which boiler 18 is placed. Similarly a porton of branch 16 is passed through the refrigcrating chamber 32' which is isolated from the refrigerating chamber 33 in which boiler 19 is placed,and similarly a portion of branch 17 is passed through a refrigerating chamber 34 isolated from the refrigerating chamber 35 in which boiler 20 is placed.

Leading from the vapor space of boiler 18 to suction pipe 11, through a control valve C of common form is a' pipe 36. Similarly a pipe 37 leads from the vapor space of boiler 19 through a control valve 0 to pipe 11. The inlet end of pi e 11 communicates with the vapor space 0 boiler 20. A con trol valve, similar to valve C and C, may be placed in pipe 11, if desired, between boiler the inlet side of the valve may not be carried below a desired minimum.

The expansion valves E are of the well known type and construction such thatthe pressure of liquid refrigerant discharged therethrough will be less than the supply pressure and said valves are adjustable so that any desired difference in pressure may be obtained.

Control mechanism M of the well known type is provided for automatically breaking the energizing circuit of the motor of the compressor 10 when it has reduced the vapor pressure in boiler 20 to a desired minimum, and for automatically closing said circuit whenever the vapor pressure in boiler 20 exceeds a desired maximum. With a volatile refrigerant, such forinstance as S0 the use of which is contemplated in the presentapparatus, the capacity of abstraction of .heat from a surrounding medium is dependent upon thepressure. under which the liquid refrigerant is normally maintained.

In other words, such a liquid refrigerant at a given pressure has a normal temperature so that the liquid refrigerant will volatilize and abstract heat from the surrounding medium until the temperature of the surrounding medium has been reduced to a temperature'substantially equal to the normal temperature of the refrigerant at the pressure at which volatilization ceases.

In operation valves E are set to supply refrigerant, through their respective pipes 15, 16 and 17, tov the respective boilers 18, 19 and 20, at a slightly higher pressure than the normal pressure at which volatilization is to cease in said boilers; control valves C,

C are/set so that the vapor pressure in their respective boilers 18 and19'may not be reduced by the compressor below desired minimums (which may be different for the two.

boilers); and the automatic starting-and stopping mechanism M will be so set that,

-when the vapor pressure in the suction line erating chambers 31, 33 and 35 will be dependent upon the settings of the control yalves C and C and of the automatic starting and stopping mechanism which controls the compressor.

The minimum temperatures attainable in chambers 30, 32 and 34 will be respectively higher than the minimum temperatures attainable in chambers 30, 33 and 35'.

By this arrangement the heat-absorbing elements (pipes 15, 16 and 17 in chambers 30, 32 and 34 respectively. and boilers 18, 19 and 20 in chambers 31, 33 and 35 respectively) may be constantly supplied from a single source with adequate amounts of liquid refrigerant, each of said heat-absorbing elements having a predetermined refrigerating value, as to minimum attainable temperatures, so that different refrigerating effects may be attained through awide range by the operation of a single regenerating unit i. e. the compressor and condenser 10-13.

'I claim as my invention:

1. A refrigerating system comprising two boilers of the constant liquid-level type, a compressor, connections between the vapor spaces of said boilers and the suction side of 'the compressor, one of said connections comprising a control valve limiting the suction effect of the compressor on the associated boiler, a refrigerant supply pipe between said boiler and the condenser, means controlled by liquid-level in'each boiler for controlling refrigerant flow into said boiler, an expansion 'valve ineach supply pipe, four relatively isolated. refrigerating chambers in two of which the boilers are mounted and two of which are respectively traversed by portions of the two supply pipes between their respective expansion valves and boilers,

I and means dependent upon pressure in boiler vapor space for starting and stopping the compressor.

2. A refrigerating system comprismg two boilers of the constant liquid-level type, means for extracting exhausted'refrigerating medium from said boilers and thereby reducing pressure within said boilers, means for limiting the effect of sald pressure-reducing means relative to one of sand bollers, means connected to the discharge side of said pressure-reducing means for increasing the pressure in the medium extracted from the boilers, a condenser receiving said medium from said pressure-increasing means, pipes connecting the discharge side of saidcondenser with each of said boilers, an expansion valve in each of said pipes. two isolated chambers each traversed by a portion of one of said pipes between its expansion valve and boiler, means controlled by liquid-level in each boiler for controlling flow of refrigerating medium into the boiler, and'two isolated chambers each containing one of the boilers.

3. A refrigerating system comprising two boilers of the constant liquid-level type, a compressor, connections between the vapor spaces of said boilers and the suction side of the compressor, a refrigerant supply pipe between said boiler and the condenser, means controlled by liquid-level in each boiler for controlling the refrigerant flow into said boiler, an expansion valve in each supply pipe, four relatively isolated refrigerating chambers in two of which the boilers are mounted and two of which are respectively traversed by portions of the two supply pipes between their respective expansion valves and boilers, and means dependent upon pressure in boiler vapor space for starting and stopping the compressor.

In witness whereof, I, FRANKLIN B. HUNT, have hereunto set my hand at Chicago, Illinois, this 31st day of July, A. D. one thousand nine hundred .a nd thirty.

" FRANKLIN B. HUNT. 

